Dr. Catherine Bewerse (Tupper)

I began research in high school, and having been working with shape memory alloys since 2003. I ended up going to University of Central Florida for my undergraduate degree, where I earned a BS in Mechanical Engineering. During my time there I took an internship at Los Alamos National Laboratory, which I continued for a year after graduating. There I worked with neutron diffraction, characterizing texture and strain evolution of shape memory alloys under temperature and stress. I also did undergraduate research at the University of Central Florida with Dr. Raj Vaidyanathan, who is one of Professor Dunand's alumni from MIT.

At Northwestern University, I am co-advised by David Dunand and Cate Brinson. I am studying shape memory porous structures primarily for bone implant applications. To produce a variety of porosities and morphology in these structures, I use powder pressing will various space-holders. I am working on creating fully interconnected 3D porosity structures. These structures will be used to study the relationship between bone cell growth, proliferation, and their local stress state. While it is known that cells are influenced by the local stress state of the scaffold they are growing on, the specific relationship is not understood. My scaffolds will be compressively loaded in vitro, mimicking walking on a hip joint for example, to quantify the effects of stress on bone cell growth and differentiation. Between the complex geometrical shapes and material deformation behavior, these structures have a very complex strain field. To better understand the distribution around pores, and the corresponding propagation of the phase transformation during loading, Digital Image Correlation (DIC) is used on simplified 2D arrays of "pores" to calculate a 2D strain field.